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* distributed with this work for additional information *
* regarding copyright ownership. The ASF licenses this file *
* to you under the Apache License, Version 2.0 (the *
* "License"); you may not use this file except in compliance *
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* *
* http://www.apache.org/licenses/LICENSE-2.0 *
* *
* Unless required by applicable law or agreed to in writing, *
* software distributed under the License is distributed on an *
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package org.apache.james.jdkim.impl;
import java.io.OutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.apache.james.jdkim.api.BodyHasher;
import org.apache.james.jdkim.api.SignatureRecord;
import org.apache.james.jdkim.canon.DebugOutputStream;
import org.apache.james.jdkim.canon.DigestOutputStream;
import org.apache.james.jdkim.canon.LimitedOutputStream;
import org.apache.james.jdkim.canon.RelaxedBodyCanonicalizer;
import org.apache.james.jdkim.canon.SimpleBodyCanonicalizer;
import org.apache.james.jdkim.exceptions.PermFailException;
public class BodyHasherImpl implements BodyHasher {
private static final boolean DEEP_DEBUG = false;
private SignatureRecord sign;
private DigestOutputStream digesterOS;
private OutputStream out;
public BodyHasherImpl(SignatureRecord sign) throws PermFailException {
MessageDigest md;
try {
md = MessageDigest.getInstance(sign.getHashAlgo().toString());
} catch (NoSuchAlgorithmException e) {
throw new PermFailException("Unsupported algorythm: "
+ sign.getHashAlgo(), e);
}
try {
sign.validate();
} catch (IllegalStateException e) {
throw new PermFailException("Invalid signature template", e);
}
int limit = sign.getBodyHashLimit();
// TODO enhance this to use a lookup service.
boolean relaxedBody = SignatureRecord.RELAXED.equals(sign
.getBodyCanonicalisationMethod());
if (!relaxedBody
&& !SignatureRecord.SIMPLE.equals(sign
.getBodyCanonicalisationMethod())) {
throw new PermFailException(
"Unsupported body canonicalization method: "
+ sign.getBodyCanonicalisationMethod());
}
DigestOutputStream dout = new DigestOutputStream(md);
OutputStream out = dout;
if (DEEP_DEBUG)
out = new DebugOutputStream(out);
out = prepareCanonicalizerOutputStream(limit, relaxedBody, out);
setSignatureRecord(sign);
setDigestOutputStream(dout);
setOutputStream(out);
}
static OutputStream prepareCanonicalizerOutputStream(int limit,
boolean relaxedBody, OutputStream dout) {
OutputStream out = dout;
if (limit != -1)
out = new LimitedOutputStream(out, limit);
if (relaxedBody)
out = new RelaxedBodyCanonicalizer(out);
else
out = new SimpleBodyCanonicalizer(out);
return out;
}
/**
* @see org.apache.james.jdkim.api.BodyHasher#getOutputStream()
*/
public OutputStream getOutputStream() {
return out;
}
/**
* @see org.apache.james.jdkim.api.BodyHasher#getSignatureRecord()
*/
public SignatureRecord getSignatureRecord() {
return sign;
}
private DigestOutputStream getDigesterOutputStream() {
return digesterOS;
}
/**
* @see org.apache.james.jdkim.api.BodyHasher#getDigest()
*/
public byte[] getDigest() {
return getDigesterOutputStream().getDigest();
}
public void setSignatureRecord(SignatureRecord sign) {
this.sign = sign;
}
public void setDigestOutputStream(DigestOutputStream dout) {
this.digesterOS = dout;
}
public void setOutputStream(OutputStream out) {
this.out = out;
}
}